Adaptive Immunity Flashcards
What are the 3 main functions of the lymphatic system?
- drainage of tissue
- absorption and transport of fatty acids and fats
- immunity
Where does the ‘recognition’ phase in the adaptive immune response take place?
secondary lymphoid organs
What are the secondary lymphoid organs?
lymph nodes, the spleen and mucosal associated lymphoid tissue
What are the primary lymphoid organs?
bone marrow and thymus
What happens in primary lymphoid tissue?
blood cells are produced and receive their early training
What happens at the thymus?
maturation of T cells that were generated in the bone marrow
What happens at the secondary lymphoid organs?
activation of lymphocytes by antigens
What does the spleen do?
filters blood of antigens, defective or worn out blood cells and microorganisms and contains many kinds of blood cells
What is a major feature of all secondary lymphoid organs except the spleen?
high endothelial venules
What is meant by ‘high endothelial venules’?
‘doorway’ through which B and T cells enter the secondary lymphoid organs from the blood - essentially gaps between endothelial cells
What is an example of mucosal-associated lymphoid tissue?
Peyer’s patches
How do some lymphocytes become memory cells?
stimulation of naive lymphocytes by exposure to antigen
Where are B cells produced?
bone marrow
What do B cells mature into?
plasma cells
What do plasma cells do?
produce antibodies
What do B cells express?
surface immuoglobulin which is the antigen receptor for the B cell
Why is it more important to make T cells tolerant than B cells?
B cells cannot make antibodies without the help of T cells
What is an antigen?
any substance capable of triggering an immune response
What structures on antigens characterise the antigens to immune cells as being foreign?
epitopes which protrude from its surface
What are the basic features of an antibody (structurally)?
- made up of a heavy and a light chain
- has Fc region (stem bit)
- Y shaped
What are the 2 types of antibody light chain?
lambda and kappa and they have no effect on Ig class
What do heavy chains on antibodies define?
class of Ig
How many different classes of antibody are there?
5
What are the 5 classes of antibody and what is their function?
IgM - good at fixing complement and opsonisation
IgG- good opsoniser
IgA- protects mucosal surfaces, resistant to stomach acid
IgE- defends against parasites, causes anaphylactic shock and allergies
IgD- no known Ab function
